This invention relates to removing articles from a vertical, wheel blow molding machine and more particularly to apparatus for removing articles from such a machine of the type wherein the mold sections close and open parallel to the wheel axis, and for depositing such articles on an adjacent takeaway conveyor.
In the past, blown articles have been removed in finished or semi-finished (i.e. with waste flash still attached) form from the discharge area of wheel blow molding machines by gravity ejection onto a chute feeding a conveyor supplying a surge hopper. An operator at the hopper outlet then usually manually fed the articles to the next downstream work station, such as a trimming machine. If the articles could be mechanically controlled during removal from the molding machine such that they could be forwarded directly to the next work station, manpower could be reduced and the hopper bypassed. Also, forwarding directly from the molding machine to the trimming machine insures a more uniform temperature of the plastic at the time of trimming and therefore a more uniformly trimmed article.
U.S. Pat. No. 3,770,098 discloses controlled removal of containers from molds of a wheel machine of the type using hinged "book" molds wherein one section is rigidly mounted on a support and the other is pivotaly attached thereto for opening and closing the mold.
An equally commercially popular wheel blow molding machine utilizes molds wherein each section simultaneously moves horizontally parallel to the machine axis during opening and closing. This type of movement has the advantage over other forms of evenly contacting the hot, tangentially fed parison with both sections of the closing mold at the same time, thus avoiding any uneven chilling effects which can occur when one portion of the mold contacts the parison appreciably ahead of another. With this type of machine employing horizontally operating molds, the formed part, just prior to release for gravity ejection from the machine, is conventionally suspended momentarily on the mold parting line in the mold-open portion of the machine periphery between a pair of article knockout pins and fully out of engagement with the recessed portions of each section. A more complete description of this type of machine is set forth in U.S. Pat. No. 3,365,748.
Removal of molded articles in a controlled manner from a machine of the type just-mentioned has however, up till now, not been possible as far as is known, the system of the aforementioned 3,770,098 patent presenting substantial clearance problems between the arcuately downwardly descending arms of the system therein disclosed and the continuously moving mold sections of the machine.